Effects of different seasons on the outcome of in vitro fertilization and embryo transfer: a retrospective cohort study

Objective: fertilization-embryo transfer (IVF-ET)-assisted pregnancy. Methods: We retrospectively analyzed data from 1,413 infertile patients who received IVF and antagonist ovulation induction program in the Reproductive Medicine Center of our hospital from January 2019 to December 2023. Based on seasons, they were divided into the spring group, summer group, autumn group, and winter group. The general information, embryo status, and pregnancy outcome of patients in different groups were compared. Results: < 0.05). Conclusion: For infertile patients undergoing controlled ovarian stimulation with an antagonist protocol, the rate of blastocyst formation in the spring was higher than that in the summer. There might be a potential interaction between the year and the season.